This is so gorgeous. It's very light and airy, as it should be, seeing as the character is flying through the clouds.
However, it may be my computer screen, but I am missing the iridescence you are speaking of. I see blues and some green and yellows, but it seems all the other colors are not there. Unless you didn't use them in the first place. n.n If in that case, most people think that iridescence is normally associated with the whole rainbow. Despite missing these colors, your character looks very soft and fluffy, as if I could reach out and feel its fur.
Overall, a wonderful job! And congrats on the feature.